The present invention relates to a countersinkable tap for liquid containers. In particular the invention relates to a tap having a tamper evident device. The tap is particularly suitable for use with beverage cans, such as, for example, party kegs of beer.
EP 0 912 407 B1 discloses a liquid container with such a countersinkable tap. The tap has an outer tube and an inner tube displaceable in the inter tube. The inner tube can be extended out of the outer tube and thereby brought from a closing position into an open position. In the open position coinciding bores allow liquid flow out of the container. Attached to the inner tube is a pivotable pull grip having an orifice. A lead seal, which is welded to a flange of the outer tube, is inserted through the orifice. The flange rests on the can wall.
When the grip is pivoted off of its seat in order to pull the inner tube into the open position, the lead seal breaks off.
This design presents at least two disadvantages. First, the lead seal has to be manufactured and fastened separately. Second, the glass to be filled is normally held under the tap when the liquid is being drawn off, therefore it is not possible to prevent the broken-off head of the lead seal from falling into the glass. This, of course, presents hygiene problems.
Another tamper-evident device has been developed (DE 19835569 A1) by the assignee of the present patent application. The device includes a pin which is integrally formed on the abutment of the outer tube. The pin is sheared off, when the grip is rotated, by a blade arranged on the grip. The sheared off pin falls down vertically from the can edge, and, although the risk of it falling into the drinking glass is, albeit greatly reduced, nevertheless the risk is not prevented completely.
Another disadvantage of this design is that, at relatively low temperatures, the plastic pin becomes so hard that it is difficult to shear off. However, this tamper-evident device does have the advantage of not requiring the separate fitting of the lead seal.
DE 3803153 A1 discloses a protective cap for kegs. The kegs have webs which break open at predetermined breaking points when the cap is removed. These webs remain on the cap, thus avoiding the situation where these caps penetrate into the keg closure. By contrast, with such a cap, it is not possible for a tap to be opened.
A similar xe2x80x9ckeg snap lidxe2x80x9d with a lead seal function, which has xe2x80x9csnapping-off barbsxe2x80x9d, is described in xe2x80x9cBrauweltxe2x80x9d [xe2x80x9cBrewing Worldxe2x80x9d], no 43, 187, page 1958. This cannot be used, either, as a tap for beverage cans.
One object of the present invention is, therefore, to provide a tap with tamper-evident device which does not require the separate welding on of a lead seal. The tap can therefore be manufactured concomitantly in a simple way using injection molding. This design prevents detached parts from falling down, the tamper-evident device having a permanent and visible deformation after the tap has been opened for the first time. Another object of the invention is to provide a design that prevents the tap from jamming.
According to the present invention, a tap for a liquid container including a tamper-evident device is provided. The tap includes an outer tube and an inner tube positioned inside the outer tube. The inner tube is configured to rotate within the outer tube to open the tap and allow liquid in the container to flow through the tubes. The tap includes a grip connected to the inner tube and including a tab positioned to interact with a wedge located on the outer tube. The grip is configured so that when the inner tube is rotated to open the tap the tab contacts the wedge and is permanently deformed to indicate that the tap has been tampered with.
Preferably, the tab includes a thickened portion having a wedge shaped corresponding to the shape of the wedge located on the outer tube. The tab may include a notched portion positioned to allow the tab to bend at the notch. The tab may be connected to the grip by any of a number of suitable methods including welding or sealing. The tap may further include a slot located on the outer tube for receiving a spigot located on the inner tube. The slot may be curved and include radial and axial regions. The spigot may include a rounded portion for allowing movement of the spigot in the curved slot.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.